abdera-user mailing list archives

Hi All,
I wanted to confirm that the way I have achieved support for multiple
providers by a single AbderaServlet, does not create any other issues.
Let me breif you through my requirement and the way I achieved it.
Requirement:
I am building an AbderaServlet to serve 3 different kind of COLLECTIONS. I
want URL for each of the COLLECTION cascaded as shown below, I will
consider COLLECTION names as collectionA, collectionB and collectionC. And
corresponding ENTRY as entryA, entryB and entryC. I have created 3
collection adapters to serve my 3 COLLECTIONS, CollectionAdapterA,
CollectionAdapterB and CollectionAdapterC
URL
TargetType
Method to be called
/collectionA/
COLLECTION A
getFeed() of CollectionAdapterA
/collectionA/ANY/
ENTRY A
getEntry() of CollectionAdapterA
/collectionA/ANY/collectionB/
COLLECTION B
getFeed() of CollectionAdapterB
/collectionA/ANY/collectionB/ANY/
ENTY B
getEntry() of CollectionAdapterB
/collectionA/ANY/collectionB/ANY/collectionC/
COLLECTION C
getFeed() of CollectionAdapterC
/collectionA/ANY/collectionB/ANY/collectionC/ANY/
ENTRY C
getEntry() of CollectionAdapterC
My solution to achive:
The idea is to created 3 different Providers to serve each kind of
COLLECTION. TargerResolver of 3 providers are set such that if satisfies
above requirement, as given below
Provider
Collection Regex
Entry Regex
ProviderA
/collectionA/
/collectionA/ANY/
ProviderB
/collectionA/ANY/collectionB/
/collectionA/ANY/collectionB/ANY/
ProviderC
/collectionA/ANY/collectionB/ANY/collectionC/
/collectionA/ANY/collectionB/ANY/collectionC/ANY/
Now, the problem is I cannot register 3 providers to a single
AbderaServlet. I noticed from the AbderaServlet source, it holds a single
protected Provider field. I have to dynamically choose any one of these
providers depending on the Request URL. I noticed that a method "service"
defined in AbderaServlet will be called on each Request. In the service
method it uses its protected Provider instance.
So, I extended AbderaServlet as "CustomAbderaServlet". The
CustomAbderaServlet intializes holds all my 3 Providers. I override
"service" method where I check the Request URL and choose appropriate
Provider, code is pasted below,
public class AdaptersAbderaServlet
extends AbderaServlet {
protected ServiceManager manager;
protected Provider providerA;
protected Provider providerB;
protected Provider providerC;
public void init() throws ServletException {
manager = createServiceManager();
/* Initializing providers */
providerA = new providerA();
providerA.init(getAbdera(), getProperties(getServletConfig()));
providerB = new providerB();
providerB.init(getAbdera(), getProperties(getServletConfig()));
providerC = new providerC();
providerC.init(getAbdera(), getProperties(getServletConfig()));
log.debug("Created providers " + datasourceProvider + ", " +
botypeProvider);
}
@Override
protected void service(
HttpServletRequest request,
HttpServletResponse response)
throws ServletException, IOException {
/* Call to get a suitable provider depending on the request */
Provider myProvider = getProvider(request);
RequestContext reqcontext =
new ServletRequestContext(myProvider, request);
FilterChain chain = new FilterChain(myProvider,reqcontext);
try {
output(
request,
response,
chain.next(
reqcontext));
} catch (Throwable t) {
error("Error servicing request", t, response);
return;
}
log.debug("Request complete");
}
private Provider getProvider(HttpServletRequest request) {
String path = request.getRequestURI();
if(path.contains("collectionC"))
return providerC;
else if(path.contains("collectionB"))
return providerB;
else if(path.contains("collectionC"))
return providerA;
// TODO Handle this situation
return null;
}
}
So far its working fine for me.
My questions are:
1. whether this change is fine to have Or will will it leads to any other
issues?
2. Is there any other way to achieve the same?
3. If there is no other way, is it possible for Abdera to consider this
requirement and provide users a way to give their custom providers
depending upon the Request URL? Or Is abdera framework is such a that a
Servlet should be associated with a single provider?